The maximum number of symbol errors in a block that can be guaranteed to be corrected by the Reed-Solomon algorithm is t = (n-k)/2. Why is the width of ERR_CNT the number of binary bits required to represent (n-k)?
The ERR_CNT bus gives the number of errors, erasures, and punctures that were corrected in the most recent output block. Because the decoder corrects the code block if 2e + E <= n-k, the bus width is equal to the number of binary bits required to represent (n-k). "e" is the number of errors and "E" is the number of erasures.